1. Field of the Invention
The present invention relates to a speaker cabinet and a speaker device, and more particularly to the structure of a speaker cabinet in which a speaker driver is fixed and a speaker device including the speaker cabinet.
2. Description of the Related Art
Speaker devices are generally constructed as shown in FIG. 3. This speaker device 51 includes a speaker cabinet 52. In the speaker cabinet 52, the frame of a speaker driver 53 generating sound by being vibrated back and forth is fixed to a side board 54a, and a box-type hollow cabinet 54, which is arranged such that a base board 54b is put into contact with a floor surface F, is contained.
In the speaker device 51 containing the speaker cabinet 52, undesirable vibration transmitted from the speaker driver 53 is largely absorbed by the cabinet 54. The rest of the vibration that is not absorbed is transmitted to the floor surface F from the base board 54b of the cabinet 54 and is diffused.
In an audio system using the speaker device 51 as a related speaker device, an auxiliary speaker (tweeter) for reproducing a high-frequency range and having a small amplitude, etc., is added. At this time, since the auxiliary speaker is required to be made smaller and to satisfy certain conditions for directivity, etc., as shown in FIG. 3, an auxiliary speaker 71 is generally placed on and fixed to the speaker cabinet 52 of the speaker device 51.
However, when constructed in this way, the following problems occur. That is, in the speaker device 51, undesirable vibration is mostly absorbed by the cabinet 54 of the speaker cabinet 52, and only the vibration left unabsorbed is diffused from the base board 54b of the cabinet 54 to the floor surface F.
On the contrary, when a large sound volume is generated in the speaker driver 53, since the undesirable vibration also increases, it becomes difficult for the cabinet 54 of the speaker cabinet 52 to fully absorb the vibration. Then, the amount of vibration which can be diffused from the base board 54b of the cabinet 54 to the floor surface F is also limited and, as a result, the speaker cabinet 52 undulates back and forth at the center in the vicinity of the base board 54b of the cabinet 54.
Under such conditions, the top surface of the speaker cabinet 52, that is, the top board 54c of the cabinet 54, greatly undulates back and forth and, since the amplitude at this portion becomes the greatest, the auxiliary speaker 71 having a small amplitude placed on the top board 54c of the cabinet 54 greatly undulates. As a result, the position of the sound source of the auxiliary speaker 71 becomes unstable and the main objective of adding the auxiliary speaker 71 cannot be obtained.